In an internal combustion engine mounted laterally on a vehicle with the intake side of the engine facing forward, it is known to extend the branch pipes of an intake manifold from the front side of the cylinder head in a forward and upward direction along an arcuate path, and position a fuel delivery pipe for distributing fuel to a plurality of fuel injectors of the engine between the branch pipes and the front side of the cylinder head. See WO2012/014378A1, for instance.
According to this prior art, an intake chamber member forming an upper end part of the intake manifold is connected to the free ends of the branch pipes so that the intake manifold is required to have a high level of stiffness in order for the intake manifold to support a load caused by a frontal crash of the vehicle. As a result, the weight of the intake manifold has to be increased, and the manufacturing cost rises. Therefore, there is a desire to favorably protect a fuel delivery pipe from a load caused by a frontal crash of the vehicle without unduly increasing the weight of the intake manifold.